Light emitting diodes (LEDs), as a low-power consumption, environmentally friendly light source, are widely applied in the fields such as lighting and backlight display. To make an LED emit stable light, a current flowing through the LED is required to be relatively constant, and especially, when LEDs are used as a backlight source for a display, the currents flowing through each LED chip are further required be equalized as much as possible, in order to achieve a desirable display effect.
Therefore, how to achieve precise control of a current flowing through an LED with a simple circuit structure is a technical problem urgent to be solved